Instantiating New prefab to have same velocity as Existing prefab

Hi guys.
I'm going wrong somewhere in my code for a Unity 2D game.
I'm spawning a missile to have the same speed as a different version of it, currently it just spawns and sits flat on the ground. both have a bounce texture and the first missile is told to delete itelf and spawn a new missile prefab upon collision with ground in the same place, this works - adding the movement values, does not?
Thanks!
Nick

void playFlash()
{
GameObject playFlash = (GameObject)Instantiate(Flash);
playFlash.transform.position = transform.position;
playFlash.transform.rotation = transform.rotation;
playFlash.GetComponent<Rigidbody2D>().velocity;
}